Question

I would like to check for string “tDDDDD” where D has to be digits and should not be more than the length (minimum 4, maximum 5) of it.

No other characters allowed.

Currently my code checks like this,

m = re.match('^(t)(\d+)', changectx.branch())

But is also allows t12345anythingafterit.

I changed the regular expression to

'^(t)(\d\d\d\d)(\d)?$'

Is this correct or any smart way of doing it?

Answer 1

Your regular expression will work, but you could also use this regular expression:

r'^t\d{4,5}$'

The {4,5} is a quantifier that means the previous token must occur between 4 and 5 times.

The parentheses are only necessary here if you wish to capture the matching parts of the string.